Slide valves



Feb. 6, 1968 J. c. E. FLINT 3,367,243

SLIDE VALVES Filed Nov. 19, 1965 4 Sheets-Sheet l HGJ.

Q @D2J BY M Feb. 6,' 1968 J. c. E. FLINT 3,367,243

SLIDE VALVES Filed Nov. 19, 1965 4 Sheets-Sheet 2 HHIHI NVENVOR ATTOEN EY BY @JM/MMM Feb. 6, 1968 1. c. E. FLINT 3,367,243

SLIDE VALVES Filed Nov. 19, 1965 4 Sheets-Sheet .'j

INvENTo ATTQQNEY Feb. 6, 1968 J. c. E. FLINT 3,367,243

SLIDE VALVES Filed Nov. 1.9, 1965 4 Sheets-Sheet fl n INVENTQE E @JM/f @www ATTORN EY .lohn C. E. Flint, @half as Npiments, to towt teilbar-n, England assigner, by lUndts Limited, CheliFiled Nov E9, 1%5, Fier. No. $433,576 Claims priority, ermany, .la d, No5, @J3/de i3 Clarins. (Cl. @ll-4MB This invention relates to slide valves, and more particularly to such slide valves when a plurality thereof are arranged in parallel manner to form a banked unit, each slide valve being of the kind including a displaceable member of rectangular cross section whose side faces are substantially at and eo-operate with respective and adjacent casing plate surfaces, each displaceable member being movable selectively from a neutral position to at least one operative position for the control of an associated liuid-pressure-operable service. rlhe casingof such a banked unit has at least one connection thereto for pressure iuid supply and also has at least one exhaust connection therefrom, unloader ports being provided in each displaceable member, so inter-communicable that when all the displaceable members are in their neutral positions, the presure iiuid supplied to the banked unit is passed through all the unloader ports directly to exhaust. Such a btnked slide valve unit is hereinafter referred to as a slide valve unit of the kind described.

According to this invention, at least one displaceable member of a slide valve unit of the kind described is capable of controlling its associated service doubleacting manner and is movable to a further or float position, thereby to be capable of placing both sides of the double-acting service in communication with exhaust, that displaceable member, when in this further or float position, having substantially no restrictive effect upon the normal operation of each other displaceable member of the unit between its said neutral and operative positiens.

The arrangement of unloader ports is such that when said one displaceable member is in its further or iloat position when the other displaceable member or members of the bank are in their neutral positions, a route is provided between the fluid pressure supply connection and the exhaust connection, but when any one of said other displaceable members is moved away from its neutral position, that route is closed, both sides of the service associated with said one displaceable member being mainte-.ined in communication with exhaust.

The displaceable members may be movable in linear manner, being rectangular in cross-section in a plane at right-angles to their direction of motion.

By so providing one displaceable member of the banked valve unit with a further and float position, the service associated therewith, for example a scoop-operating jack of an earth-moving vehicle, is placed in communication Patented Feb. 6, i868 on either side with exhaust so that the scoop can drag or slide along the ground with tne piston of the jack freestroking in its cylinder as the scoop follows the undulations of the ground.

The banked valve unit may include check valves, One associated with each displaceable member and also i11- elude a single pressure relief valve for the complete valve unit.

Detent means may be provided for mechanically holding the said one displaceable member in its further and float position.

One embodiment of the invention will now be particularly described by way of example with reference to the accompanying drawings, of which,

FGURE l is a plan view of a banked slide valve unit having three displaceable members,

EGURE 2 is a cross-section taken along the line Il-II on FIGURE l,

FlGURE 3 is a cross-section taken along the line l-ill on a part of FGURE 2,

FIGURE 4 is a cross-section similar to that of FG- URE 3, but with the slider in a different position, and,

FIGURE 5 is a schematic diagram of the slide valve unit shown in FGURES 1 to 4.

Referring to FEGURE l of the drawings, a slide Valve unit il of the kind described includes an inlet casing 12 which incorporates a liquid pressure supply connection 13 and a pair of service line connections i4 and 15 which respectively lead through pipes i6 and 17, to a doubleacting service S1.

Adjacent the casing plate 12 is a slider frame 18 and continuing along the bank a further casing plate 19, a further slider frame Ztl, another casing plate 2i, another slider trame 22 and finally a drain casing plate 23, itself having a drain connection 24. All the casing plates and slider frames of the bank are held together in sealed relation by suitable long bolts passing through them and having nuts applied thereto.

The casing plate i9 has service line connections 25 and 2e connected by way of respective pipes 27 and 23 to a further double-acting service S2. The casing plate Z1 likewise has service line connections 29 and 30, also respectively connected by way of pipes 31 and 32 to another double-acting service S3.

All the double-acting services S1, S2, and S3 are in the form of telescopic jacks.

With reference now to FIGURES 2 to 5, each slider frame, indicated diagrammatically in FIGURE 5, respectively has displaceable valve members in the form of sliders 33, 34, and 35'.

Each of the sliders is linearly displaceable in its slider frame under the control of an operating rod as at 36 in FIGURE 2. A spring-box 37 is provided in association with the respective operating rod 36 to bias the respective slider to its neutral position.

Each operating rod is connected to its slider by means of a tongue-and-slot connection 38.

The spring-box 37 is housed within a cover member 39 itsetlf carrying a bracket 4t) to which a respective control lever di is pivotally mounted at d2. The control lever 41 is connected by means of a link 43 to the operating rod 36.

Each slider 33, 34 or 35 includes a webbed elongated slot Lid cut through it as shown in FGURE 2, this slot :inning parallel with the longitudinal axis of the slider, and balance ports 45, de are provided on either side of and spaced apart from the slot d4 in the linear direction or motion of the slider. The sliders 33 and 34 have 3 straight end edges 47, 48 and 49, S0, respectively, while the slider has a straight end edge 51 at its left-hand end as shown in FIGURES 2 and 5 and a straight edge 52 havinga semi-circular projection 53 to the right.

Each of the sliders have inching slots 54 and 55 cut in the direction of motion of the slider on the operable end edges of the elongated slot 44. Also the left-hand and right-hand edges in FIGURES 2 and 4 of the drawings of the sliders have inching slots 56 and 57 cut therein.

Each displaceable member also includes an unloader port 58 cut through it, being positioned beneath and in a plane parallel with the elongated slot 44. In the sliders 33 and 34 the unloader ports 58 have unloader balance ports 59 and 60 cut completely through the slider, and spaced away from, on either side of, the unloader port.

The balance ports 45, 46 and unloader balance ports 59, 60 are intended to provide hydrostatic balance in the transverse sense for the respective sliders.

The sliders 33 and 34 associated with the services S1 and S2 are intended to control these services in doubleacting manner, but the slider 35, as well as being intended to control the service S3 in double-acting manner, is also capable of moving to a further or float position wherein the jack is placed in communication on either side with drain so that a device, operated by the jack, in this case a scoop of an earth-moving vehicle, can slide along the ground with the piston of the jack free-stroking f in its cylinder as the scoop follows the undulations of the ground. In FIGURES 4 and 5 of the drawings the slider 35 is in this float position when itis in its extreme right-hand position in the drawings, as later described.

All the unloader ports 58 have inching slots 61, 62 cut in their operable end edges.

A detent device comprising a spring-loaded ball 63 is provided in the slider frame 22, as shown in FIGURE 2, co-operable with a slot 64 and an indent 65 formed to the left of this slot. The indent 65 corresponds to the float position of the slider 35 so that when the slider is moved to the extreme right-hand position in the slider frame, the detent 63 engages the indent 65 mechanically to lock the slider in its float position.

With particular reference to FIGURES 2 to 5, the slider 35 has no unloader balance port formed to the right in the drawing of the unloader port 58, but only has balance port means at a single position to the left in the drawing of the unloader port. The arrangement comprises a pair of rectangular recesses 66 and 67 cut in the side faces of the slider and in communication with each other by means of three transverse and vertically-spaced ports 68,

69 and 70. To the left of these ports and formed within the body of the slider is an internal .duct 71 which extends downwardly from the elongated slot 44 in substantially parallel manner with the recesses 66 and 67. Three transverse and vertically-spaced pairs of ports 72, 73 and 74 extend from this duct to both side faces of the slider.

In FIGURE 2 of the drawings the slider 35 is shown in its neutral position, while in FIGURE 5 the slider 35 is shown in its normal operative position to the right of the neutral position with the service S3 pressurised `for contraction.

Also in FIGURE 5 the sliders 33 and 34 are shown in their neutral positions in which the balance ports 45 and 46 are in alignment with the service pipes 16, 17, 27, 2S respectively so that the services S1 and S2 are held in a hydraulically locked condition.

Referring to FIGURE 3 of the drawings, the slider 35 is shown in its neutral position in which the unloader port 58 places a passage 75 in communication with a passage 76 which leads to tank.

As shown clearly in the schematic representation of the three slider valve bank in FIGURE 5, a pump 80 drawing liquid from a reservoir 81 delivers pressure liquid through line 82 from which feeder passages 83 and 84 lead to the elongated slots 44 in the sliders 33 and 34. The feeder passages 83 and 84 each incorporate a check valve 85 and 86, which permits ilow towards the slot 44 but prevents reverse ilow back towards the line 82.

The line 82 continues downwardly in the drawing to a relief valve 87, the downstream side of which is connected through a line 88 to the reservoir 81.

An open-centre line 89 is branched from the line 82 just downstream of the pump 86 and is taken to the face of the casing plate 12 adjacent the unloader ports 58 of the slider 33. As shown, with the slider 33 in its neutral position the line 89 is placed in communication with the line 90. The line 90 continues to the next casing plate 19 and with the slider 34 in its neutral position is connected through to the line 75, also shown in FlG- URE 3. The line 75 similarly is taken to the casing plate 21 and with the slider 35 in its neutral position the line 75 as shown in FIGURE 3 connects through the port 53 with the drain line 76.

A branch line 92 taken from the line 75 in the casing plate 21 leads to the elongated slot 44 in the slider 35. The line 92 incorporates a check valve 93 which, like the check valves and 86, permits flow of liquid towards the slider but prevents flow of liquid away from the slider.

The system is such that whatever the position of the sliders 33, 34, 35, the elongated slots 44 are open respectively to the lines 83, 84 and 92.

The lines 89, 90, 75 and 76 are so arranged in conjunction with the unloader ports 58 that when all the sliders are in their neutral position, a direct route is provided between the inlet connection 13 and the drain connection 24 so that the pump 80 delivers direct to the reservoir 81, by-passing the relief valve 87 thereby avoiding the generation of unnecessary heat within the valve block.

Chambers 94 and 95 provided at the end of the respective sliders 33, 34 and 35 are placed in communication with drain by suitable passages, running along the length of the bank, shown diagrammatically in FIGURE 5 by clearances 96, 96a along the upper and lower edges of the sliders and by linking passageways 97 and 98 connecting the slider frames 18, 20 and 22 together and by a passageway 99 which links the frame 22 to line 88 and thus to reservoir 81.

If, in operation of the slide valve unit, any one of the sliders 33, 34, 35 is moved away from its neutral position, the unloader route provided by the lines 89, 90, 75 and 76 is closed because the appropriate unloader port 58 is closed. Hence, pressure can then build up in the line 82 and is available at all the elongated slots 44. If it is the slider 33 for example which is moved and such movement is to the left in the drawing, then the slot 44 directs pressure liquid into the pipe 16 while the straight end edge 48 opens the pipe 17 to the drain chamber 95. Hence the service S1 is extended.

If the slider 33 is instead displaced to the right in the drawing away from its neutral position the converse occurs, so that pressure liquid is supplied through the pipe 17 and exhausted through the pipe 16 and chamber 94 so that the service S1 contracts.

Similarly, if either the slider 34 or the slider 35 is moved in either direction from the neutral position, the services S2 or S3 are appropriately operated.

In FIGURE 5 of the drawings the slider 35 is shown in its normal operative position to the right of the neutral position in which the unloader port 58 is closed, thereby closing the 4unloader route, and in which pressure liquid is supplied through the pipe 32 to the service S3, while the other side of the service is placed in communication with the drain chamber through the pipe 31, the sen/ice thereby contracting.

When the slider 35 is moved to its extreme right-hand position as shown in FIGURE 4 of the drawings, that is to its float position in which the service S3 is able to freestroke to permit the scoop operated thereby to follow the undulations of the ground, the pipe 31 is placed in communication with the drain chamber 94 while the pipe 32 is placed in communication with reservoir through the S elongated slot de, the duct 71, the ports 72, '73, 7d, the yrecesses 66 and d?, ports 59 and the drain line 76.

Such communication of the duct 71 and ports 72, '73 and 74 with drain is afforded by virtue of the alignment of the ports 72, 73, '7dwith the passage '75 as clearly shown in FIGURE, 4, the flow path following the dotted arrows from the passage 75 which is then placed in communication with the drain line 7d through the recesses 66 and 67 which overlap them.

The arrangement of pressure lines and passageways associated with the slider 35 and the positioning of the slider 35 immediately adjacent the drain connection 214, is such that when this slider is in its Float position it has little or no restrictive effect upon the normal operation of the other two sliders 33 and 3d. It will be seen that the direct unloader route from the pump to reservoir is still open when the slider 35 is in its float position and is thus only closed when either ofthe sliders 33 and 3d are moved away from their neutral positions.

The inching slots provided in association with the elongated slots in the sliders, with the end edges of the sliders, and with the unloader ports, are such that precise and accurate control in the service pressurising and exhausting, and also in the unloading function is achieved.

Although in the embodiment above described only two normally-operating sliders are provided in association with the slider capable of float control, in other embodiments, any other desired number of normally-operating sliders are provided in association with one or more sliders capable of float control.

Again, certain of the sliders in a banked unit, other than that or those intended for iloat control, may not be associated with double-acting services, but may nstead be associated with single-acting services, rotary hydraulic motors, or any other device capable of being controlled by the sliders, the porting of the sliders being modied accordingly.

Although in the rst embodiment above-described with reference to the drawings the sliders are displaceable linearly in their slider frames, the invention is in no way limited thereto, as in other embodiments the sliders are instead displaceable angularly, or in rotatable manner about a fixed rotational axis, the porting and balance porting being modied appropriately to suit the precise form of slider used.

In alternative embodiments of the invention, the slider capable of iloat control may be so ported and of such shape, and its associated passageways and porting in the casing so arranged, that the slider can be positioned at any station along the bank, at the same time this slider having little or no impairing effect upon the normal operation of the remaining sliders in the bank.

Further, in other embodiments, to avoid the building up of undesirably high pressures in the two service lines from the slider capable of lloat control to its associated double-acting service these lines are each provided with a service line relief valve carried upon the appropriate casing plate. Conveniently these relief valves discharge directly to the drain zones of the slider block.

The invention is in no way limited to its application to liquid systems as in other embodiments it is with advantage applied to systems of the pneumatic or other gaseous type.

l claim as my invention:

1. A slide valve unit comprising in combination: a plurality of slide valves arranged in parallel, banked manner; a plurality of casing plates disposed adjacent said valves; each said slide valve including a displaceable member of rectangular cross section having side face surfaces which are substantially ilat and co-operate with respective and adjacent casing plate surfaces, means maintaining each displaceable member movable selectively from a neutral position to at least one operative position for the control of an associated uid-pressure-operable service; a casing for the unit having at least one connection thereto for a pressure fluid supply and also at least one exhaust connection therefrom; unloader ports provided in each displaceable member and so inter-communicable in series relation that when all of the displaceable members are in their neutral positions the pressure uid supplied to the lbanked unit is passed through all the unloader ports directly to exhaust; and at least one of said displaceable members having means maintaining it operable to control its associated service in double-acting manner and being movable to a further or float position placing both sides of an associated double-acting service in communication with exhaust, said one displaceable mem-ber when in said further position having substantially no restrictive elfect upon the normal operation of each other displaceable member of the unit between its said neutral and operative positions.

2. A slide valve unit as claimed in claim 1, wherein the arrangement of unloader ports is such that when said one displaceable member is in its further or float position and when the other displaceable members of the bank are in their neutral positions a route is provided between the liquid pressure supply connection and the exhaust connection, but when any one of said other displaceable members is moved away from its neutral position, that route is closed, both sides of the service associated with said one displaceable member being maintained in communication with exhaust.

3. A slide valve unit as claimed in claim 1, wherein the displaceable members are movable in linear manner, being rectangular in cross-section in a plane at rightangles to their direction of motion.

d. A slide valve unit as claimed in claim 1, and further including check valves, one associated with each displaceable member.

5. A slide valve unit as claimed in claim 1, and also including a single pressure relief valve, for the complete unit.

d. A slide valve unit as claimed in claim 1, and having detent means for mechanically holding the said one displaceable member in its further or oat position.

'7. A slide valve unit as claimed in claim 1, wherein each of said displaceable members includes an elongated pressure slot communicable at all times with a source of pressure huid and capable, when the member is displaced away from its neutral position, of directing pressure fluid to one side at least of the associated service.

S. A slide valve unit as claimed in claim 7, wherein each displaceable member has at least one balance port provided in association with said elongated pressure slot, which balance port is cut through the thickness of the member and serves to fluid balance the member in the transverse sense.

9. A slide valve unit as claimed in claim 8, wherein said one displaceable member movable to a further or lioat position, includes at least one recess formed therein alongside said unloader port and spaced therefrom in the direction of motion of the member, said recess member isolated from said unloader port when the member is in its neutral position, but being in communication therewith when the member is in its further or lloat position.

1t?. A slide valve unit as claimed in claim 9, wherein a duct is provided within said one displaceable member communicating said elongated pressure slot with porting formed on at least one side face of the member on that side of the recess remote from the said unloader port.

11. A slide valve unit as claimed in claim 10, wherein when said one displaceable member is in its further or float position, said porting, said recess and said unloader port are placed iu communication with exhaust, thereby placing one side of the service also in communication with exhaust.

12. A slide valve unit as claimed in claim 10, wherein two of said recesses are formed in said one displaceable member adjacent the unloader port, which recesses are connected by means of porting out transversely in the 7 member, said recesses thereby affording unloader balance port means for fluid balance of the member in the transverse sense in the vicinity of the unloader port.

13. A slide valve unit as claimed in claim 7, wherein inching slots are provided, cut in the direction of sliding of each displaceable member, in the operable edges of the elongated pressure slot, in the operable end edges of the member and in the operable end edges of the un loader port.

References Cited UNITED STATES PATENTS EDGAR W. GEOGHEGAN, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No. 3,367,243 February 6, 1968 John C. E. Flint It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent Should read as corrected below.

In the heading to the printed specification, line 7, for "Germany" read Great Britain Signed and sealed this 15th day of April 1969.

(SEAL) Attest:

EDWARD J. BRENNER Commissioner of Patents Edward M. Fletcher, Jr.

Attesting Ufficer 

